The present invention relates to a lubricating oil delay part, and, more particularly, to a delay part for an internal combustion engine having a cylinder block, crankcase and a divided oil pan held on the crankcase.
Oil baffles are known for example, from the journal ATZ 89 (1987) 2, Page 69, for acting as so-called oil planing devices and arranged between the cylinder block and the oil pan. These oil baffles have the purpose of reducing the foaming of the oil, particularly at high rotational speeds.
In the German Patent DE-35 31 352 C1, a honeycombed insert in the recess of an oil pan surrounds the suction pipe of the oil pump and, through its chambers, the oil reaches the suction pipe in a time-delayed manner and, as a result, defoamed. This type of an arrangement cannot be used if there is insufficient installation space available in the recess.
It is an object of the present invention to largely defoam the foamed oil in an internal-combustion engine.
This object has been achieved in accordance with the present invention by extending a delay part in a horizontal area situated in a plane to border the oil pan. A space situated above the delay part by way of oil passages arranged adjacent to an outer boundary is connected with a space situated underneath.
The delay part arrangement prevents a short-circuit-type intake of foamed oil. When the delay part is arranged adjacent to a surface provided with sealing devices between the crankcase and the oil pan, the foamed oil dripping out of the crank space must first flow on the delay part to its boundary and through the oil passages arranged there and must flow back under the delay part to the centrally arranged strainer. The resulting forced time delay until the intake causes a good defoaming of the oil.
The same advantage is achieved in the case of an arrangement of the delay part adjacent to an area provided with sealing devices which is part of a horizontally divided oil pan between the deep part of the oil pan used as the storage tank and the lid which closes it on the bottom. The oil which flows back into the storage tank approximately in the center from the crankcase must cover the above-mentioned delay path to the strainer situated in the oil pump between the delay part and the lid.
In an advantageous embodiment of the invention, the delay part is held on an oil pump and extends close to the inner edge of the area provided with the sealing devices. For the fastening, the delay part has an opening into which the strainer is fitted and the edge area of which is detachably connected with a flange of the oil pump.
In a further embodiment, the boundary has a flange-shaped configuration and is braced in the area. Advantageously, a sealing device which acts on both sides may be integrated into the boundary so that the normal separate sealing devices are not required. In the range of the screwed connection between the parts bordering on the area, spacer sleeves are integrated into the sealing device so that a pressure exists which is uniform over the entire circumference and prevents a crushing of the sealing device.
The delay part may be simply produced as a stamped sheet metal part or as a molded plastic part. Subsequently, the sealing device is vulcanized on, together with the spacer sleeves, as elastomers. In the case of a plastic construction, ribs which extend from the direction of the boundary toward the opening for the strainer may easily be arranged on the underside of the delay part facing the oil sump. In the case of accelerations, these ribs force the oil situated in the sump along the strainer.
It is also advantageous for the oil situated below the delay part, in the case of strong accelerations, to displace itself considerably less than the part of the lubricating oil quantity situated above because the oil from the oil sump can move to the top only comparatively slowly by way of the oil passages. This ensures a constant flow around the strainer.